A major development in the field of public health and cancer prevention took place on May 18, 2021 when the U.S. Preventive Services Task Force provided updated recommendations regarding the age to begin screening for colorectal cancer. Adults should initiate screening for colorectal cancer at the age of 45, according to the new guidelines. This is a significant change by the task force, which previously recommended in its 2016 guidelines that screening for this cancer begin at the age of 50.

This update is a welcome one to oncologists like me who have witnessed a continued rise in the rates of colorectal cancers being diagnosed in young patients. Over 10% of all colon cancers are diagnosed in patients under the age of 50, a fact that led the American Cancer Society to recommend in 2018 that screening begin at age 45. We know that the best outcomes for patients occur when colorectal cancer is detected at its earliest stages, and this is made possible by screening tests.

The U.S. Preventive Services Task Force is a panel of health experts that includes physicians and epidemiologists who gather the most updated evidence in order to provide recommendations for healthcare providers across the country. Cancer screening recommendations are of particular public interest as they offer a guide to both primary care physicians about which tests to order and to insurance companies about which tests are covered. The new guidelines were finalized after a draft proposal was made public in October 2020 that foreshadowed this announcement.

Why is colorectal cancer on the rise in young people?

This is the question that is of significant interest to scientists, physicians, and public health experts alike. The reasons are not yet clear, but hypotheses include changes in diet, rising rates of obesity, sedentary lifestyles, and widespread use of antibiotics. This epidemiologic change is not unique to the United States as it has been observed in countries across the globe. We are continuing to study the molecular differences between early onset colorectal cancer and colorectal cancer of older adults to better understand this phenomenon.

What does this mean for me?

People who are considered to be at normal risk should discuss colorectal cancer screening with their primary care providers beginning no later than age 45. If you have concerns about a strong family history of colorectal cancer or a personal history of blood in your stool or low iron or blood levels, you should discuss colorectal cancer screening sooner than 45.

What does it mean to be normal vs. high-risk?

High-risk patients include those with a first-degree family member (i.e. parent or sibling) with a history of colorectal cancer, patients who have been diagnosed with inflammatory bowel disease, and those who have been diagnosed with a genetic condition that predisposes them to colorectal cancer. Most patients who do not have these risk factors are considered to be average or normal risk. Other potential colorectal cancer risk factors that are important to consider but do not necessarily change the age at which to begin screening include cigarette smoking, heavy alcohol use, obesity and Type 2 diabetes.

What are my options for colorectal cancer screening?

Although a colonoscopy is the preferred method of screening for many healthcare providers because it can both make a cancer diagnosis and allow for removal of early pre-cancerous growths (polyps), there are a number of other approved screening tests. If you have a normal colonoscopy, then a repeat colonoscopy is recommended 10 years later for screening. This interval may be shorter if any polyps are detected.

Flexible sigmoidoscopy is a screening test that is similar to a colonoscopy, but it does not evaluate the entirety of the colon. Thus, it is recommended that this be performed at more frequent intervals and potentially in combination with stool-based tests. There are multiple approved stool-based tests that evaluate for blood or abnormal DNA, which may indicate the presence of colorectal cancer, and need to be performed every one-two years. An additional screening test utilizes a CT scan to visualize the inside of the colon and rectum. If CT or stool-based screening tests are utilized, any abnormal result is usually further investigated with a colonoscopy.

Although we are alarmed at the rise in colorectal cancer in young adults, we applaud these updated recommendations by the USPSTF. By initiating routine colorectal cancer screening at the age of 45, I believe we will be saving more lives by making diagnoses at an earlier, curable stage. Many young people will benefit by having pre-cancerous polyps found and removed prior to the growths having the chance to develop into cancerous tumors. I encourage you to discuss these new recommendations with your primary care provider and help to reverse the troubling trends in the incidence of younger adults with colorectal cancer.